Recycled Arabic gum as a replacement for starch in self-reducing mill scale-based briquettes

Steelmaking produces large quantities of iron-rich by-products and their recycling improves resource efficiency and reduces waste generation. This work investigates the potential for utilizing mill scale to produce self-reducing briquettes assessing the effectiveness of recycled Arabic gum as a sustainable binder compared to conventional starch. The briquettes were produced by combining the mill scale with different reducing agents: olive pomace biochar pyrolyzed at 750 (OP750) and 350 °C (OP350), and cupola furnace dust (CFD). By using Arabic gum instead of starch, an improved resistance to impact was observed for each mixture (1000 for OP750 and CFD versus 767 and 191, respectively). Recycled Arabic gum, also, limited the swelling of each mixture and promoted the sintering of the briquettes. On the contrary, the starch favored an increase in volume (maximum 153.62%) until 1200 °C. Furthermore, the Arabic gum enhanced the reduction capacity of the mixture while preventing chemical or morphological variations in the reduction products and leading to an increase of up to 9.06% in the degree of metallization with OP350. Overall, most the results obtained using Recycled Arabic gum exceeded the industrial benchmark, confirming the feasibility of its usage as a substitute for starch in self-reducing briquettes.